热加工和高压加工对纯化番茄多聚半乳糖醛酸酶的失活动力学

Inactivation kinetics of purified tomato polygalacturonase by thermal and high-pressure processing.

作者信息

Fachin Diana, Smout Chantal, Verlent Isabel, Ly Nguyen Binh, Van Loey Ann M, Hendrickx Marc E

机构信息

Laboratory of Food Technology, Department of Food and Microbial Technology, Faculty of Agricultural and Applied Biological Sciences, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, B-3001 Leuven, Belgium.

出版信息

J Agric Food Chem. 2004 May 5;52(9):2697-703. doi: 10.1021/jf030531h.

DOI:10.1021/jf030531h

PMID:15113178

Abstract

Tomato polygalacturonase (PG) was extracted from ripe tomatoes and purified by cation exchange and gel filtration chromatography. Cation exchange chromatography yielded two peaks with PG activity: the first peak was identified as PG2 (the heat labile form) and the second one as PG1 (the heat stable form). Both PG2 and PG1 presented a molar mass of 42 kDa when analyzed by SDS-PAGE and an isoelectric point >9.3. Thermal inactivation of purified tomato PG2, at pH 4.4, in the temperature range from 53 to 63 degrees C, followed first-order kinetics. Combined pressure-temperature inactivation of tomato PG2 was studied at 5-55 degrees C/100-600MPa. Under all pressure-temperature conditions, PG2 inactivation followed first-order kinetics. Purified tomato PG1, although more thermostable than PG2, showed a pressure stability very similar to that of PG2. These results indicate that high-pressure processing is an efficient alternative to inactivate tomato PG without the need for applying high temperatures.

摘要

番茄多聚半乳糖醛酸酶（PG）从成熟番茄中提取，并通过阳离子交换和凝胶过滤色谱法进行纯化。阳离子交换色谱产生了两个具有PG活性的峰：第一个峰被鉴定为PG2（热不稳定形式），第二个峰为PG1（热稳定形式）。通过SDS-PAGE分析时，PG2和PG1的摩尔质量均为42 kDa，等电点>9.3。在pH 4.4条件下，纯化的番茄PG2在53至63摄氏度温度范围内的热失活遵循一级动力学。研究了番茄PG2在5-55摄氏度/100-600MPa条件下的压力-温度联合失活情况。在所有压力-温度条件下，PG2失活均遵循一级动力学。纯化的番茄PG1虽然比PG2更耐热，但显示出与PG2非常相似的压力稳定性。这些结果表明，高压处理是一种有效的替代方法，无需高温即可使番茄PG失活。